Question

I’m trying to add +1 to a number in my XML document, and if its just one no problemo, but… If I want to update 2 nodes it goes wrong?

Here is what I have tried:

$xml = new DOMDocument("1.0", "ISO-8859-1");
$xml->formatOutput = true;
$xml->preserveWhiteSpace = false;
$xml->loadXML('<?xml version="1.0"?>
<friends>
  <friend id="1">
    <name>MyTest</name>
    <games>5</games>
    <wins>3</wins>
  </friend>
</friends>');

echo "<xmp>OLD:\n". $xml->saveXML() ."</xmp>";

$library = $xml->documentElement;
$xpath = new DOMXPath($xml);
$xpath2 = new DOMXPath($xml);

$result = $xpath->query('//friend[@id="1"]/games');
if($result){

    $cgames = $xpath->query('//friend[@id="1"]/games')->item(0);
    $cgames = $cgames->nodeValue;
    $result->item(0)->nodeValue = $cgames+1;

    $cwins = $xpath->query('//friend[@id="1"]/wins')->item(0);
    $cwins = $cwins->nodeValue;
    $result->item(0)->nodeValue = $cwins+1;

    echo "<xmp>NEW:\n". $xml->saveXML() ."</xmp>";
}

When doing this I only update and its new value would be 4? It should be 6 and should be 4… What am I doing wrong?

Please help and thanks in advance 🙂

Answer 1

Add $result2 since you are trying to update /wins on /games search

$result = $xpath->query('//friend[@id="1"]/games');
$result2 = $xpath->query('//friend[@id="1"]/wins');

if($result){
    $cgames = $result->item(0)->nodeValue;
    $result->item(0)->nodeValue = $cgames+1;
}

if($result2){
    $cwins = $result2->item(0)->nodeValue;
    $result2->item(0)->nodeValue = $cwins+1;
}

echo "<xmp>NEW:\n". $xml->saveXML() ."</xmp>";

and remove $xpath2 = new DOMXPath($xml);, you don’t need 2 XPaths

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